Consider two thin identical conducting wires covered with very thin insulating material. One of the wires is bent into a loop and produces magnetic…

Consider two thin identical conducting wires covered with very thin insulating material. One of the wires is bent into a loop and produces magnetic field $\displaystyle \mathrm{B}_1$, at its centre when a current I passes through it. The second wire is bent into a coil with three identical loops adjacent to each other and produces magnetic field $\displaystyle \mathrm{B}_2$ at the centre of the loops when current I/$\displaystyle 3$ passes through it. The ratio $\displaystyle \mathrm{B}_1: \mathrm{B}_2$ is :